Internal combustion motor



Dec. 20, 1932. D. HEAD 1,891,326

INTERNAL COMBUST I ON MOTOR Filed Feb. 24. 1930 @cg- WW W Patented Dec. 20, 1932 nnnw READ, or CHICAGO, ILLINOIS INTERNAL COMBUSTION MOTOR Application filed February 24, 1980. Serial No.'480,570.

This invention relates to improvements in internal combustion motors, and-more par-' ticularly to a novel design for the piston and cylinder head of such motors calculated-to improve their efliciency and performance.

With the development of the high speed, hi h compression motor for automotive uses, the need-for more complete and perfect combustion of the explosive mixture in the cylinder has been recognized and considerable effort has been directed toward designing the combustion chambers so as to eliminate the various factors believed to contribute to power loss in the cylinder.

The object of the resent invention is to provide a design for t e combustion chamber and piston calculated to further improve the conditions of combustion within the cylinder through increased turbulence of the explosive mixture during the intake and compression strokes, thereby creating a more homogeneous mixture uniform and slower burning, and consequent reduction in detonation and resulting reverberation.

Considering the L-head type of motor, that is, the type in which the inlet andexhaust valves are located on the same side of the cylinder, the combustion chamber is considered to include all of the space above the piston when thesame is at top dead center, the volume of this space bearing a predetermind ratio to the total displacement of the cylinder as a factor in determining the maximum compression. These factors, however, have been more or, less standardized in motor design, and, therefore, the present disclosure is con cerned more With the shape and conformation of the surfaces of the combustion chamber.

A preferred embodiment of my invention is shown in the accompanyin drawing of a typical L-head motor in whic Figure 1 is a view in vertical section through one of the cylinders of the motor as taken on line 11 of Figure 2, and

Figure 2 is a view in cross section through the head of the motor as taken on line 2-2 of Figure l. 4

Following the standard design of motors of the L-head type, the cylinder 1 is offset to one side of the motor bloc, and in the cylinder is a piston 2 carried at the upper end of a connecting rod 3. On one side of the cylinder are the inlet andexhaust ports 4- and 5 which connect with the inlet and exhaust manifolds respectively. The inner ends of the ports open upwardly and form the seats for theinlet and-exhaust valves 6 and 7, their stems extending downwardly through vertical bearings 8 and connected with theusual timing 2 mechanism. 1

. As is customary in motor construction, a hollow casting or head 9 is bolted to the cyl-. inder bloc 1, and extends over the cylinder and the valves forming the com'bustion'chamber. In this instance the bottom surface of the head is formed, a wall 10 having a domeshaped se ment 10a extending over the valve ports, and an'inverted' dome-sha ed or con- ,vexed segment 10?) over the cylind r and projecting downwardly into the upper end of the same in concentric relation to its walls. The wall 10 is cast integral with the marginalportions 11 of. the head which bear flatwise against the to of the cylinder bloc with their inner edges escribing the limits of a symmetrical pattern 12 v(Figure 2) encircling the top of cylinder'and the valve ports.

At the top of the dome-like segment 10a of the wall'lO and invertical alignment immediately above the valves is a threaded bore in which the spark plug'13 is mounted, with its terminal points projecting just within the combustion chamber, p r

Referring to the piston 2, thesame is of 35 standard design and construction, except for the head 2a which has the form of a semispherical .concave wall complementing the convex segment 10b of the cylinder head. In

the top dead center position these complementing concavo-convex surfaces ofthe piston and cylinderheads are separated by a narrow clearance space 14 which forms a part of the combustion chamber.

In accordance with the well known principle of operation of the four cycle internal combustion engine, the explosive mixture is drawn into the cylinder during the intake (down) stroke of the piston with the opening of the inlet valve at the commencement of each cycle, and during the compression (up) ton to form a narrowclearance space comstroke the charge is compressed and then igmunicating with said combustion chamber nited just in advance of the completion of the when the latter 1s in top dead center position.

compression stroke. Without some means Signed at Chicago, 111., this 21st day of within the combustion chamber for breaking February, 1930.

up the stream of incoming mixture, it ordinarily tends to become more or less Stratified ordivided withthe result that the mixture burns more rapidly in some regions of the combustion chamber, and under compression explodes with a sudden detonation, while other portions burn more slowly due to being diluted by the inert burned gas remaining after the previous exhaust stroke.

HoWever,-if a definite turbulence is set up in the combustion chamber as the. incoming mixture is drawn in, more uniform conditions are established, which is reflected in a more even rate'iof flame propagation and smoother delivery of power to the piston.

In the present design this is promoted by the complementary concavo-convex faces of the piston and cylinder heads, in that the stream of incoming mixture on entering the cylinder come in'contact with these rounded surfaces and is broken up into many streams flowing in different directions, thns setting up a generalturbulent condition and thus distributing themixture uniformly throughout the combustion space. This is true during the compression as well as the intake stroke, inasmuch as the gases are compressed between two oppositely rounded surfaces, and consequently greater efiiciency and smoother power impulse is to be expected,

I-claim as my invention:

1.- In an internal combustion engine, the combination on; cylinder. having a head m vided with at substantially semi-spherical portion projecting into saidcylinder' and presenting an uninterrupted convex surface, and a piston in'said cylinder having a concave head complementing the convexity of said cylinderheidr f 9. In an internal combustion engine, the combination of a cylinder having a head depressed into said cylinder in the form of a semi-spherical wall presenting an uninterrupted convex surface arranged symmetrical- 1y with respect to the axis of the cylinder, and a piston having a concave head complementthe convexity of said cylinder head In an internalcombustion engine, the combination of a cylinder, a piston in said cylinder having a head provided with a substantiaily semi-spherical depression symmetrically disposed with respect to the axis of said cylinderga cylinder head forming a combustion chambercommunicating with the upper end of said cylinder and having a semispherical convex portion complementing said concave depression in said piston head and providing an uninterrupted surface projects ing axially into said cylinder in close proximity to the concavity in the head of said pis- DREW HEAD. 

